Use the following procedure for a recharge of completely discharged battery.

Measure tension on battery plugs by the exact voltmeter. If value of the measured size is lower 10 in, current of charging will be very low, and on charging extra time will be required.

Put the charger on the high place. Some chargers have the scheme of protection against the return polarity preventing charging at the wrong connection with battery plugs. Completely discharged battery has no sufficient tension to put this scheme in action even if wires are connected correctly. It will lead to the fact that the battery will not be charged. Therefore follow special instructions of the producer of chargers that the charger turned on and began to charge the battery with low voltage.

Regulators of tension and current are provided in chargers. Values of time necessary for battery charging depending on various values of tension, are given below.

If the charge received by the battery cannot be measured after the expiration of time of charging, the battery should be replaced.

If the received charge is measured in process of charging, then the battery is serviceable, and charging should be finished in the usual way.